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Inouye, L. Y.

Publications and source records attributed to Inouye, L. Y..

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Operation of high power converters in parallel

High power converters that are used in space power subsystems are limited in power handling capability due to component and thermal limitations. For applications, such as Space Station Freedom, where multi-kilowatts of power must be delivered to user loads, parallel operation of converters becomes an attractive option when considering overall power subsystem topologies. TRW developed three different unequal power sharing approaches for parallel operation of converters. These approaches, known as droop, master-slave, and proportional adjustment, are discussed and test results are presented.

Decker, D. K.↗
NASA NTRS1992

Operation of high power converters in parallel

Three different unequal power sharing approaches for parallel operation of converters - droop, master-slave, and proportional adjustment - are discussed. The approaches have been incorporated in the breadboard dc-dc converter units used in the space station power management and distribution dc test bed at the Lewis Research Center, where the system operation has been verified.

Decker, D. K.↗
NASA NTRS1991

Multikilowatt power electronics development for spacecraft

Attention is given to several multikilowatt power electronic components developed by TRW for the Space Station Power Management and Distribution test bed at NASA Lewis Research Center. These components include a 12.5-kW DC-DC converter, a 6.25-kW battery charge/discharge regulator, an 82-channel sequential shunt unit, a 10-A remote power controllers, and three different types of 1-kW load converters. TRW is also monitoring the development of 120-V fuses for space applications. The authors discuss these developments and provide steady-state and dynamic performance parameters.

Decker, D. K.↗
NASA NTRS1980

Power processing technology for spacecraft primary ion propulsion

Advanced technologies developed in support of Ion Propulsion power processing, including the power circuitry portion of the Series L-C Resonant Inverter, Beam Supply, power components, packaging and heat pipe cooling of the 30 cm Ion Engine Power Processor are described. Both the transistorized and SCR versions of the Series L-C Resonant Inverter Beam Supply are discussed. A BIMOD Ion Thruster/Power Processor Prototype Assembly is undergoing environmental and life testing. These advanced technologies can be applied advantageously to other applications of future high power space power processing equipment.

Biess, J. J.↗
NASA NTRS1977

Extended performance electric propulsion power processor design study. Volume 1: Executive summary

Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30cm ion thruster power processor with a beam supply rating of 2.2kW to 10kW. Extensions in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. Preliminary electrical design, mechanical design, and thermal analysis were performed on a 6kW power transformer for the beam supply. Bi-Mod mechanical, structural, and thermal control configurations were evaluated for the power processor, and preliminary estimates of mechanical weight were determined. A program development plan was formulated that outlines the work breakdown structure for the development, qualification and fabrication of the power processor flight hardware.

Biess, J. J.↗
NASA NTRS1977

Extended performance electric propulsion power processor design study. Volume 2: Technical summary

Electric propulsion power processor technology has processed during the past decade to the point that it is considered ready for application. Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30 cm ion thruster power processor with a beam power rating supply of 2.2KW to 10KW for the main propulsion power stage. Extension in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. A detail design was performed on a microprocessor as the thyristor power processor controller. A reliability analysis was performed to evaluate the effect of the control electronics redesign. Preliminary electrical design, mechanical design and thermal analysis were performed on a 6KW power transformer for the beam supply. Bi-Mod mechanical, structural and thermal control configurations were evaluated for the power processor and preliminary estimates of mechanical weight were determined.

Biess, J. J.↗
NASA NTRS1977

Development of a standardized control module for dc-to-dc converters

The electrical performance of a power processor depends on the quality of its control system. Most of the existing control circuits suffer one or more of the following imperfections that tend to restrict their respective utility: (1) inability to perform different modes of duty cycle control; (2) lack of immunity to output filter parameter changes, and (3) lack of capability to provide power component stress limiting on an instantaneous basis. The three lagging aspects of existing control circuits have been used to define the major objectives of the current Standardized Control Module (SCM) Program. Detailed information on the SCM functional block diagram, its universality, and performance features, circuit description, test results, and modeling and analysis efforts are presented.

Yu, Y.↗
NASA NTRS1977

Electric prototype power processor for a 30cm ion thruster

An electrical prototype power processor unit was designed, fabricated and tested with a 30 cm mercury ion engine for primary space propulsion. The power processor unit used the thyristor series resonant inverter as the basic power stage for the high power beam and discharge supplies. A transistorized series resonant inverter processed the remaining power for the low power outputs. The power processor included a digital interface unit to process all input commands and internal telemetry signals so that electric propulsion systems could be operated with a central computer system. The electrical prototype unit included design improvement in the power components such as thyristors, transistors, filters and resonant capacitors, and power transformers and inductors in order to reduce component weight, to minimize losses, and to control the component temperature rise. A design analysis for the electrical prototype is also presented on the component weight, losses, part count and reliability estimate. The electrical prototype was tested in a thermal vacuum environment. Integration tests were performed with a 30 cm ion engine and demonstrated operational compatibility. Electromagnetic interference data was also recorded on the design to provide information for spacecraft integration.

Biess, J. J.↗
NASA NTRS1974

Power processor for a 30cm ion thruster

A thermal vacuum power processor for the NASA Lewis 30cm Mercury Ion Engine was designed, fabricated and tested to determine compliance with electrical specifications. The power processor breadboard used the silicon controlled rectifier (SCR) series resonant inverter as the basic power stage to process all the power to an ion engine. The power processor includes a digital interface unit to process all input commands and internal telemetry signals so that operation is compatible with a central computer system. The breadboard was tested in a thermal vacuum environment. Integration tests were performed with the ion engine and demonstrate operational compatibility and reliable operation without any component failures. Electromagnetic interference data were also recorded on the design to provide information on the interaction with total spacecraft.

Biess, J. J.↗
NASA NTRS1974

High voltage series resonant inverter ion engine screen supply

A high-voltage, high-power LC series resonant inverter using SCRs has been developed for an Ion Engine Power Processor. The inverter operates within 200-400Vdc with a maximum output power of 2.5kW. The inverter control logic, the screen supply electrical and mechanical characteristics, the efficiency and losses in power components, regulation on the dual feedback principle, the SCR waveforms and the component weight are analyzed. Efficiency of 90.5% and weight density of 4.1kg/kW are obtained.

Biess, J. J.↗